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Gold nanostar (AuNSt) has gained great attention in bioimaging and cancer therapy due to their tunable surface plasmon resonance across the visible‐near infrared range. Photothermal treatment and imaging capabilities including fluorescence lifetime imaging at two‐photon excitation (TP‐FLIM) and dark‐field microscopic imaging are considered in this work. Two types of AuNSts having plasmon absorption peaks centred at 600 and 750 nm wavelength were synthesized and studied. Both NSts exhibited low cytotoxicity on A549 human lung carcinoma cells. A strong emission at two‐photon excitation was observed for both NSts, well‐distinguishable from lifetimes of bio‐object autofluorescence. High efficiency in raising the temperature in the NSts environment with the irradiation of near infrared, AuNSts triggered photothermal effect. The decreased cell viability of A549 observed via MTT test and the cell membrane damaging was demonstrated with trypan blue staining. These results suggest AuNSts can be agents with tunable plasmonic properties for imaging and photothermal therapy. [ABSTRACT FROM AUTHOR]

Nanodiamond is one of the carbon families that has attracted much attention recently for its versatile spectroscopic properties; render it promising potential in optoelectronic, quantum computation, and bio/medical applications. With sizes ranging from several hundred down to single digit nanometers, nanodiamond represents a group of nanomaterial with rich surfaces both in its physical and chemical properties. Its surface and bulk consist of carbon of bonding of different nature. The sp²/sp³ hybridization forming diamond, graphite, disorder/amorphous carbons and defects are easily detectable using infrared and Raman spectroscopy and allow both easy characterization and the surface modification or conjugation with molecules of interest. Recently nanodiamond is considered as one of the most biocompatible nanomaterials. With the newly discussed defects-originated fluorescence, renders nanodiamond suitable for bio-labeling, bio-sensing and drug delivery. In this chapter, the authors review and discuss the spectroscopic studies of nanodiamond surfaces focusing on the infrared spectroscopy, Raman spectroscopy, including SERS, photoluminescence spectroscopy and lifetime analysis. Applications of these methods to detect and analyze surface structural features, surface molecular groups and macromolecules conjugations, interactions between nanodiamond surface moieties and its environments, etc. are discussed. These open new possibilities for bio-medical applications, for multimodal imaging, sensing, and controllable drug delivery of nanodiamond. [ABSTRACT FROM AUTHOR]